<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="https://cdn.bootcss.com/vue/2.6.10/vue.js"></script>
    <script src="https://cdn.bootcss.com/vue-router/3.0.4/vue-router.js"></script>
    <script src="https://cdn.bootcss.com/jquery/3.4.0/jquery.js"></script>
    <style>
        * {
            margin: 0;
            padding: 0
        }

        .app {
            text-align: center;
            padding: 20px;
            max-width: 748px;
            margin-left: auto;
            margin-right: auto;
            display: -webkit-box;
            display: -ms-flexbox;
            display: flex;
            -ms-flex-wrap: wrap;
            flex-wrap: wrap;
            -webkit-box-pack: justify;
            -ms-flex-pack: justify;
            justify-content: space-between;
        }

        .container {
            width: 150px;
            height: 240px;
            padding: 10px;
            font-size: 14px;
            -webkit-box-shadow: 0 0 5px 3px rgba(51, 51, 51, .26);
            box-shadow: 0 0 5px 3px rgba(51, 51, 51, .26);
            margin-top: 20px;
        }

        img {
            width: 150px;
        }

        button {
            margin: 0 auto;
            width: 748px;
            height: 50px;
            border-radius: 2px;
            display: block;
            height: 40px;
            line-height: 40px;
            text-align: center;
            font-size: 14px;
            background: #f7f7f7;
            text-decoration: none;
            color: #258dcd;
            border:none;
        }
    </style>
</head>

<body>
	<div>
		<img src="https://img1.doubanio.com/view/photo/s_ratio_poster/public/p2541901817.jpg">
	</div>
    <div id="app">
        <div class="app">
            <div class="container" v-for="item of movies" ref="wrap">
                <img :src="item.images.small" alt="">
                <p>{{item.title}}</p>

            </div>
        </div>

        <button @click="add" v-if="addMore">加载更多</button>
    </div>
    <script>
        var url = "https://api.douban.com/v2/movie/top250"
        new Vue({
            el: "#app",
            data: {
                msg: "hello world",
                movies: [],
                addMore:false
            },
            created() {
                $.ajax({
                    url,
                    dataType: "jsonp",
                    success: res => {
                        this.movies = res.subjects;
                        this.addMore = true
                    }
                })
            },
            methods: {
                add() {
                    this.addMore = false;
                    var length = this.movies.length;
                    var url = `https://api.douban.com/v2/movie/top250?start=${length}&count=20`;
                    $.ajax({
                        url,
                        dataType: "jsonp",
                        success: res => {
                            this.movies = [...this.movies, ...res.subjects]
                            this.addMore = true;
                        }
                    })
                }
            },
        })
    </script>
</body>

</html>